Common Cold (Viral Rhinitis)

What Is It?

The common cold, also called viral rhinitis, is one of the most common infectious diseases in humans. Although the infection is usually mild and improves without treatment, it causes widespread illness and discomfort, resulting in nearly 26 million days of missed school and 23 million days of absence from work every year in the United States. The average American has one to three colds per year.

The common cold is an upper respiratory infection that is caused by a wide variety of viruses. More than 200 viruses that can cause the common cold have been identified. The biggest offender, called the rhinovirus, which causes up to 40 percent of colds, has 100 distinct types. Other important upper respiratory viruses include coronaviruses, adenovirus and respiratory syncytial virus. This incredible diversity has made the development of a vaccine for the common cold almost impossible.

Rhinoviruses, the most likely agents to cause colds, have a well-established seasonal pattern, peaking in the early fall and spring. Other viruses tend to cause winter colds, which are usually more debilitating. Despite popular belief, cold temperatures do not appear to increase either the incidence or severity of the common cold. There is no evidence that exposure to cold or rainy weather makes you more likely to catch a cold.

Symptoms

The common cold causes a group of symptoms that usually are easily recognized by patients and doctors. About 50 percent of patients will develop a sore throat, which is often the first symptom to appear because it can occur as early as 10 hours after infection. This is followed rapidly by the most common symptoms of the common cold — congested nasal and sinus passages, a runny nose and sneezing. Hoarseness and cough are less likely to occur, but they may last longer than other symptoms, sometimes for several weeks. However, high fevers and chills rarely occur.

Diagnosis

Most patients diagnose the common cold by the typical symptoms of runny nose, congestion and sneezing, and rarely consult medical attention. High fevers, severe sinus pain, shortness of breath and new wheezing are symptoms that suggest you either have something other than a cold or a complication of the cold.

Expected Duration

Symptoms typically peak on the second, third or fourth days of infection and last about one week. People are most infectious (likely to pass the cold onto others) during the first 24 hours of the illness, and they usually remain infectious for as long as the symptoms persist. Up to 25 percent of people may have persistent symptoms, such as a nagging cough that can last for several weeks. A small number of people may develop another illness, such as bacterial infections of the middle ear or the sinuses, and others may develop chronic bronchitis or worsening of asthma. These patients may have a prolonged illness.